import java.util.Stack;

public class MyQueue2 {
    private Stack<Integer> stack1;
    private Stack<Integer> stack2;
    public MyQueue2(){
        stack1 = new Stack<>();
        stack2 = new Stack<>();
    }
    public boolean empty(){
        return stack1.empty()&&stack2.empty();
    }
    public void push(int x){
        stack1.push(x);
    }
    public int pop(){
        if (empty()){
            return -1;
        }
        if (stack2.empty()){
            while (!stack1.empty()){
                stack2.push(stack1.pop());
            }
        }
        return stack2.pop();
    }
    public int peek(){
        if (empty()){
            return -1;
        }
        if (stack2.empty()){
            while (!stack1.empty()){
                stack2.push(stack1.pop());
            }
        }
        return stack2.peek();
    }
}
